4,677 research outputs found
Resilience and Vulnerability of Public Transportation Fare Systems: The Case of the City of Rio De Janeiro, Brazil
Resilience is the ability of a system to adapt, persist, and transform as a reaction to threats, which may be external or internal to the system, while vulnerability is the state of being susceptible to harm from exposure to stresses associated with environmental and social change and from the inability to adapt. Based on a study of the threats that can affect urban mobility, we identified a gap regarding the analysis of the levels of resilience and vulnerability in the face of subsidy threats that can severely affect developing countries. This article measures the level of resilience and vulnerability due to the absence of public transport fare subsidies. For this purpose, we developed an approach based on fuzzy logic and applied it in 33 administrative regions (ARs) of the city of Rio de Janeiro, Brazil. We obtained four matrices of the levels of vulnerability and resilience of each of the regions as an origin and destination. The results show that areas nearest to the downtown region and those with high-capacity transportation available (commuter train and/or subway, systems with many transfer points) are more resilient, while a high level of vulnerability is associated with low income, negative socioeconomic indicators, and the predominance of road transportation to reach jobs. The contribution of this paper is the method applied to analyse the levels of vulnerability and resilience of public transport, which includes a threat that can cause a rupture that impacts routines and job accessibility in a region
Higher depletion of lithium in planet host stars: no age and mass effect
Recent observational work by Israelian et al. has shown that sun-like planet
host stars in the temperature range 5700K < Teff < 5850K have lithium
abundances that are significantly lower than those observed for "single" field
stars. In this letter we use stellar evolutionary models to show that
differences in stellar mass and age are not responsible for the observed
correlation. This result, along with the finding of Israelian et al., strongly
suggest that the observed lithium difference is likely linked to some process
related to the formation and evolution of planetary systems.Comment: 4 pages, 4 figures, letter accepted for publication in Astronomy &
Astrophysic
New and updated stellar parameters for 90 transit hosts. The effect of the surface gravity
Context. Precise stellar parameters are crucial in exoplanet research for
correctly determining of the planetary parameters. For stars hosting a
transiting planet, determining of the planetary mass and radius depends on the
stellar mass and radius, which in turn depend on the atmospheric stellar
parameters. Different methods can provide different results, which leads to
different planet characteristics.}%Spectroscopic surface gravities have shown
to be poorly constrained, but the photometry of the transiting planet can
provide an independent measurement of the surface gravity.
Aims. In this paper, we use a uniform method to spectroscopically derive
stellar atmospheric parameters, chemical abundances, stellar masses, and
stellar radii for a sample of 90 transit hosts. Surface gravities are also
derived photometrically using the stellar density as derived from the light
curve. We study the effect of using these different surface gravities on the
determination of the chemical abundances and the stellar mass and radius.
Methods. A spectroscopic analysis based on Kurucz models in LTE was performed
through the MOOG code to derive the atmospheric parameters and the chemical
abundances. The photometric surface gravity was determined through isochrone
fitting and the use of the stellar density, directly determined from the light
curve. Stellar masses and radii are determined through calibration formulae.
Results. Spectroscopic and photometric surface gravities differ, but this has
very little effect on the precise determination of the stellar mass in our
spectroscopic analysis. The stellar radius, and hence the planetary radius, is
most affected by the surface gravity discrepancies. For the chemical
abundances, the difference is, as expected, only noticable for the abundances
derived from analyzing of lines of ionized species.Comment: 12 pages, 6 figures, 5 tables, accepted to A&
Costs Associated with Malaria in Pregnancy in the Brazilian Amazon, a Low Endemic Area Where Plasmodium vivax Predominates.
BACKGROUND: Information on costs associated with malaria in pregnancy (MiP) in low transmission areas where Plasmodium vivax predominates is so far missing. This study estimates health system and patient costs of MiP in the Brazilian Amazon. METHODS/PRINCIPAL FINDINGS: Between January 2011 and March 2012 patient costs for the treatment of MiP were collected through an exit survey at a tertiary referral hospital and at a primary health care centre in the Manaus metropolitan area, Amazonas state. Pregnant and post-partum women diagnosed with malaria were interviewed after an outpatient consultation or at discharge after admission. Seventy-three interviews were included in the analysis. Ninety-six percent of episodes were due to P. vivax and 4% to Plasmodium falciparum. In 2010, the total median costs from the patient perspective were estimated at US 216.29 for an outpatient consultation and an admission, respectively. When multiple P. vivax infections during the same pregnancy were considered, patient costs increased up to US 103.51 for a P. vivax malaria episode and US 118.51 and US 17,038.50, of which 92.4% (US$ 15,741.14) due to P. vivax infection. CONCLUSION: Despite being an area of low risk malaria transmission, MiP is responsible for a significant economic burden in Manaus. Especially when multiple infections are considered, costs associated with P. vivax are higher than costs associated with P. falciparum. The information generated may help health policy decisions for the current control and future elimination of malaria in the area
Changes in the biophysical properties of the cell membrane are involved in the response of neurospora crassa to staurosporine
Neurospora crassa is a non-pathogenic filamentous fungus widely used as a multicellular eukaryotic model. Recently, the biophysical properties of the plasma membrane of N. crassa conidia were thoroughly characterized. They evolve during conidial germination at a speed that depends on culture conditions, suggesting an important association between membrane remodeling and the intense membrane biogenesis that takes place during the germinative process. Staurosporine (STS) is a drug used to induce programmed cell death in various organisms. In N. crassa, STS up-regulates the expression of the ABC transporter ABC-3, which localizes at the plasma membrane and pumps STS out. To understand the role of plasma membrane biophysical properties in the fungal drug response, N. crassa was subjected to STS treatment during early and late conidial development stages. Following 1 h treatment with STS, there is an increase in the abundance of the more ordered, sphingolipid-enriched, domains in the plasmamembrane of conidia. This leads to higher fluidity in othermembrane regions. The global order of the membrane remains thus practically unchanged. Significant changes in sphingolipid-enriched domains were also observed after 15min challenge with STS, but they were essentially opposite to those verified for the 1 h treatment, suggesting different types of drug responses. STS effects on membrane properties that are more dependent on ergosterol levels also depend on the developmental stage. There were no alterations on 2 h-grown cells, clearly contrasting to what happens at longer growth times. In this case, the differences were more marked for longer STS treatment, and rationalized considering that the drug prevents the increase in the ergosterol/glycerophospholipid ratio that normally takes place at the late conidial stage/transition to the mycelial stage. This could be perceived as a drug-induced development arrest after 5 h growth, involving ergosterol, and pointing to a role of lipid rafts possibly related with an up-regulated expression of the ABC-3 transporter. Overall, our results suggest the involvement of
membrane ordered domains in the response mechanisms to STS in N. crassa.
Neurospora crassa is a non-pathogenic filamentous fungus widely used as a multicellular eukaryotic model. Recently, the biophysical properties of the plasma membrane of N. crassa conidia were thoroughly characterized. They evolve during conidial germination at a speed that depends on culture conditions, suggesting an important association between membrane remodeling and the intense membrane biogenesis that takes place during the germinative process. Staurosporine (STS) is a drug used to induce programmed cell death in various organisms. In N. crassa, STS up-regulates the expression of the ABC transporter ABC-3, which localizes at the plasma membrane and pumps STS out. To understand the role of plasma membrane biophysical properties in the fungal drug response, N. crassa was subjected to STS treatment during early and late conidial development stages. Following 1 h treatment with STS, there is an increase in the abundance of the more ordered, sphingolipid-enriched, domains in the plasmamembrane of conidia. This leads to higher fluidity in othermembrane regions. The global order of the membrane remains thus practically unchanged. Significant changes in sphingolipid-enriched domains were also observed after 15min challenge with STS, but they were essentially opposite to those verified for the 1 h treatment, suggesting different types of drug responses. STS effects on membrane properties that are more dependent on ergosterol levels also depend on the developmental stage. There were no alterations on 2 h-grown cells, clearly contrasting to what happens at longer growth times. In this case, the differences were more marked for longer STS treatment, and rationalized considering that the drug prevents the increase in the ergosterol/glycerophospholipid ratio that normally takes place at the late conidial stage/transition to the mycelial stage. This could be perceived as a drug-induced development arrest after 5 h growth, involving ergosterol, and pointing to a role of lipid rafts possibly related with an up-regulated expression of the ABC-3 transporter. Overall, our results suggest the involvement of membrane ordered domains in the response mechanisms to STS in N. crassa.Fundação para a Ciência e a Tecnologia (FCT), Portugal, is acknowledged for grants PTDC/BBB-BQB/6071/2014, UID/Multi/00612/2013, IF/00317/2012, and PT2020 referring to research unit 4293. FS acknowledges Ph.D. scholarship SFRH/BD/108031/2015, also from FCT
The HARPS search for southern extrasolar planets XXI. Three new giant planets orbiting the metal-poor stars HD5388, HD181720, and HD190984
We present the discovery of three new giant planets around three
metal-deficient stars: HD5388b (1.96M_Jup), HD181720b (0.37M_Jup), and
HD190984b (3.1M_Jup). All the planets have moderately eccentric orbits (ranging
from 0.26 to 0.57) and long orbital periods (from 777 to 4885 days). Two of the
stars (HD181720 and HD190984) were part of a program searching for giant
planets around a sample of ~100 moderately metal-poor stars, while HD5388 was
part of the volume-limited sample of the HARPS GTO program. Our discoveries
suggest that giant planets in long period orbits are not uncommon around
moderately metal-poor stars.Comment: Accepted for publication in A&A (replaced by version with minor
language corrections
Nord Pool Ontology to Enhance Electricity Markets Simulation in MASCEM
This paper proposes the use of ontologies to enable information and knowledge exchange, to test different electricity market models and to allow players from different systems to interact in common market environments. Multi-agent based software is particularly well fitted to analyse dynamic and adaptive systems with complex interactions among its constituents, such as the complex and dynamic electricity markets. The main drivers are the markets’ restructuring and evolution into regional and continental scales, along with the constant changes brought by the increasing necessity for an adequate integration of renewable energy sources. An ontology to represent the concepts related to the Nord Pool Elspot market is proposed. It is validated through a case study considering the simulation of Elspot market. Results show that heterogeneous agents are able to effectively participate in the simulation by using the proposed ontologies to support their communications with the Nord Pool market operator.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 641794 (project DREAM-GO) and from FEDER Funds through COMPETE program and from National Funds through FCT under the project UID/EEA/00760/2013.info:eu-repo/semantics/publishedVersio
Association of MMP-8 polymorphisms with tendinopathy of the primary posterior tibial tendon: a pilot study
Evaluation of the stability of 3D-printed paracetamol tablets stored at different relative humidities
Abstract of the communication presented at the Controlled Release Society Virtual Annual Meeting, 29 June-2 July 2020N/
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